Study And Development On Tin-Phosphor Bronze Strip With High Degree Of Accuracy And Elasticity

The quality of high precision and high elasticity tin-phosphorus bronze strips in China still lags behind that of foreign advanced countries.Especially for tin-phosphorus bronze strips with high surface quality and large volume weight,as well as products with higher yield strength than C5210 and good bending and stress relaxation properties,there is no domestic manufacturer can produce them in batches stably.Therefore,some high-quality tin-phosphorus bronze strips for lead frames,connectors and high-end continuous terminals need to be imported from abroad every year.In order to give full play to the advanced production technology,equipment and testing means of relevant enterprises,further improve the production technology and product development ability of tin-phosphorus bronze strip,catch up with or even surpass the international advanced level,we thoroughly analyze and solve the problems existing in the production process of high-precision and high-elasticity tin-phosphorus bronze strip products,and put forward reasonable production technology and control requirements in order to improve the developing of new products.This topic is specially put forward on the issue of delivery capacity and product quality level.In this paper,according to the changes of the structure and properties of alloy strip under different processing conditions,the plastic deformation mechanism of the material in the treatment process is analyzed,and the strengthening and toughening mechanism of the material is explored.The effects of different melting and casting processes,different cold rolling processes and different annealing processes on the structure and properties of alloy strip billet are emphatically analyzed.By adjusting the casting process,reducing the degree of reverse segregation,and making reasonable rolling and annealing process,the aim of high precision and high elasticity of alloy strip is achieved.By optimizing the taper of inner intermediate roll and the shape design of long fixed taper roll,the shape of the strip is controlled within 10 I.The annealing technology optimization of alloy strip solves the problemsof low mechanical properties and uneven properties of the products after annealing.By optimizing the clearance and overlap of the cutting edge,the high-precision shear strip of alloy within less than 0.10 mm can be achieved.